PHPC-605: Remove pem_file from php_phongo_manager_t

This should have been removed in f7e2b09.

Author: jmikola

php_phongo_structs.h

@@ -81,7 +81,6 @@ typedef struct {
 typedef struct {
 	PHONGO_ZEND_OBJECT_PRE
 	mongoc_client_t    *client;
-	char               *pem_file;
 	PHONGO_ZEND_OBJECT_POST
 } php_phongo_manager_t;